The subject matter disclosed herein relates generally to the field of welding filler materials, and more particularly to composition suitable for welding high-strength nickel-based alloys.
Welding is a process that can be used to join metal alloys. More broadly, any process that forms a metal weld deposit on a base metal workpiece may be considered welding. During welding operations, concentrated heat (e.g., from an electrical arc) is applied to melt portions of the base metal and a filler material, which combine in a pool of molten material that, upon solidification, forms the weld deposit. The filler material may be in the form of wire, rod, plate, etc., and generally has matching mechanical properties and/or compatible chemical composition to the base metal. A welding operation may be performed during manufacturing, repairing, servicing, and/or sculpturing of metallic components or parts. To facilitate the welding operation, it is generally desirable for the filler material and/or the base metal to have good weldability.
A superalloys, also referred to as gamma prime (γ′)-precipitation strengthened alloys, are a high-performance alloys that are used to manufacture parts that experience extreme temperatures, pressures, and/or corrosive conditions. These include iron (Fe)-, cobalt (Co)-, and nickel (Ni)-based superalloys. Superalloys have a gamma (γ) phase and a gamma prime (γ′) phase that exist in a temperature-dependent equilibrium, wherein the γ′ phase is largely responsible for the strength of the superalloy. As a superalloy is heated, the γ′ phase reversibly dissolves into the γ phase, temporarily reducing the strength of the alloy. For example, a superalloy may lose 20% or more γ′ phase as its temperature is raised from room temperature to about 1800 degrees Fahrenheit (° F.). As such, it is generally desirable for superalloys to have a substantial amount γ′ phase at room temperature to ensure sufficient γ′ phase continues to be present as the alloy is subjected to high temperature conditions. However, while a superalloy having a substantial amount of γ′ phase at room temperature tends toward higher strength, it also tends to suffer from poor weldability.